John M. Broder

WASHINGTON — Senate Republicans continued a campaign to delay confirmation of President Barack Obama’s second-term Cabinet-level nominees on Thursday, blocking a committee vote on Gina McCarthy, the president’s pick to lead the Environmental Protection Agency.

WASHINGTON — The United States and Mexico reached agreement Monday on regulating oil and gas development along their maritime border in the Gulf of Mexico, ending years of negotiations and potentially opening more than a million acres to deepwater drilling.

WASHINGTON — The House voted 255 to 172 Thursday to halt the Obama administration’s program to regulate industrial air emissions linked to climate change, delivering a rebuke to a central tenet of the president’s energy and environmental policy.

WASHINGTON — Halliburton officials knew weeks before the fatal explosion of the BP well in the Gulf of Mexico that the cement mixture they planned to use to seal the bottom of the well was unstable but still went ahead with the job, the presidential commission investigating the accident said Thursday.

WASHINGTON — The federal government announced the first national emissions and fuel economy standards for heavy vehicles Monday, one of a series of regulatory steps that the Obama administration is taking to increase energy efficiency and reduce atmospheric pollution in the absence of congressional action on climate change.

BP is warning Congress that if lawmakers pass legislation that bars the company from getting new offshore drilling permits, it may not have the money to pay for all the damages caused by its oil spill in the Gulf of Mexico.

WASHINGTON — The United States is badly lagging in basic research on new forms of energy, deepening the nation’s dependence on dirty fuels and crippling its international competitiveness, a diverse group of business executives warn in a study to be released Thursday.

The Environmental Protection Agency plans to add bisphenol-A, or BPA, a plastic widely used in food packaging and plastic bottles, to its list of chemicals of concern because of potential adverse impacts on the environment and human and animal health.

Sens. Hillary Rodham Clinton and Barack Obama battled over national security and trade in a frantic burst of last-minute campaigning on Monday as Clinton accused Obama of deception and new evidence of discord surfaced within her own camp.

With the two Democratic presidential candidates in near-deadlock and battling for every delegate, party leaders and the rival campaigns started searching in earnest on Thursday for a way to seat delegations from Florida and Michigan. But they remained deeply divided over how to do so.

Sens. Hillary Rodham Clinton, D-N.Y, and Barack Obama, D-Ill., intensified their populist appeals on Monday, responding to widespread economic anxiety and pushing the Democratic Party further from the business-friendly posture once championed by Bill Clinton.

Mitt Romney, the former Massachusetts governor who ran as a son of Michigan though he left the state nearly 40 years ago, won the Republican primary here with a message aimed at voters deeply anxious about the state’s economy and their own financial prospects.

Federal prosecutors have issued grand jury subpoenas to some of the Blackwater employees present at a Sept. 16 shooting in Baghdad in which the company’s security personnel killed 17 Iraqi civilians, lawyers in the case and government officials briefed on the matter said Monday.

The police identified Cho Seung-Hui, a 23-year-old student, as the killer of 32 people in the shooting rampage at the Virginia Polytechnic Institute, releasing new information on Tuesday about the troubled mind of a young man few people on campus knew.